1. Field of the Invention
The present invention relates to an apparatus for controlling the cooking process in a pressure cooker containing water and/or food to be cooked and heated by means of an electrical heating unit with a control circuit, wherein the temperature in or on the pressure cooker is detected and utilized by a regulating circuit of the control circuit for regulation of the heat output of the heating element. A cooking time may be preset by means of an adjustable timer and measurement of the preset cooking time begins only when a predetermined temperature between the preset cooking temperature and the evaporation temperature of the water in the pressure cooker has been reached. The time period between reaching the temperature at the beginning of the vapor phase and reaching the evaporation temperature of water in the pressure cooker is measured and the preset cooking time is adjusted on the basis of the slope of the temperature-time characteristic curve and/or the measured time period by shutting off the heating element before the preset cooking time has elapsed, with the shutting off occurring sooner the smaller the detected slope and/or the greater the measured time period.
2. Description of the Prior Art
An apparatus of this general type is disclosed in German Patent No. 33 23 399 of the applicant. Detection of the slope of the temperature-time characteristic curve and determination of the time period elapsing between reaching the temperature at the beginning of the vapor phase and reaching the temperature of evaporation of the water in the pressure cooker provide for energy saving cooking, since thereby the inertia of the whole system can be optimally utilized, depending upon the contents in the pressure cooker, by switching off the heating element before the preset time has elapsed. It is assured in every case, however, that the proper cooking temperature is maintained in the pressure cooker for the preselected cooking time.
The disadvantage of this device is that the energy saving is possible only if the cooking process continues without interruption. Often, however, it is desirable to interrupt the cooking process, for example, to add more material to be cooked. Let us mention just the addition, after an initial cooking phase, of cooking material that is to be subjected to only a brief cooking time.